It has been known a transfer system used in production factories of semiconductor devices. The transfer system includes a plurality of process apparatuses (equipment). Objects to be processed (hereinafter referred to as processing objects), such as semiconductor wafers, are sequentially transferred to respective process apparatuses to be processed in the respective process apparatuses. Such a transfer system is, for example, disclosed in JP 2004-221277 A.
The transfer system includes, in addition to the process apparatuses, stations in which the processing objects are stored before being processed by the process apparatuses, and carriers that transfer the processing objects between the stations and the process apparatuses. The processing objects are transferred from the station to the process apparatus to be processed. After being processed in the process apparatus, the processing objects are transferred to the station to be stored. Thereafter, the processing objects are transferred to another process apparatus to be processed.